Automatic fire-alarm system.



G. J. POX. AUTOMATIG FIRE SYSTEM. nzemwx 2:222- Hs. s, ms.

903,076. Patentd Nov. 3, 1908.

s-9 do OHARLES JAMES FOX, OF LONDON, ENGLAND.

AUTOMATIC FIRE-ALARM SYSTEM.

Specification of Letters Patent.

Patented Nov. 3, 1908.

Application filed April 3, 1906. Serial No. 309,603.

To all whom it may concern:

Be it known that I, CHARLES JAMES Fox, a subject of the Kin of Great Britain, and resident of 1 1 ueen treet Place, in the city of London, Eng and, lieutenant-colonel, have invented an Automatic Fire-Alarm System, of which the following is a specification.

This invention consists of a combined electric bell service and automatic fire alarm system; that is to say, a s stem in which the leads for the electric be installation serve also as leads for the fire alarm thermostat circuit, so that the leads appertaining to the thermostat in any apartment will be tested each time the electric bell in said apartment is used.

The invention also comprises a special construction of thermostat for use in said system.

The invention will be described with reference to the accompanyin diagram which illustrates a typical examp e of the application of the invention to the electric be lservice and fire alarm installations appertaining to a single apartment, the ordinary bell-push leads, and the additional leads connecting with the thermostat, being shown by thin and thick lines respectively.

A represents the ordinary service bell push in the a artment; B and O the corresponding bell an indicator res eotively; D the fire alarm thermostat in tlie apartment; E the fire alarm push (preferably of the break the glass type) which may be, say, in a corridor or other publicly accessible place adjoining the apartment; F and G the fire alarm bel and indicator res ectively (which may be, say, in a fire brigade station); and H the battery supplying current to the entire system. Obvious y however there might be separate batteries at the building contaming the apartment and at the station respectively.

According to the present invention the terminal contacts (1 o of the ordinary service bell push A in any apartment are connected to the respective members of the bat to bell and indicator circuit, not directly as as been usual heretofore, but through the respective terminals Ll d of a thermostat circuit closer D situated in the apartment. To enable this to be done while retaining the existing leads 1, 2 from the service bell push terminals (1 a, these leads are disconnected close to the push as indicated by the dotted lines, and a wire is led from each terminal contact of the ush to one of the thermostat terminals and ack to the neighborhood of the push where the wire is then connected to that member of the battery, bell and indicator circuit to which the corresponding terminal contact of the push had previously been directly connected.

The thermostat which it is preferred to employ is of a so-called three-way type having independent automatic circuit closers adapted to come into action at the same or at dltferent temperatures as may be arranged; the circuit closers (say two) having a common return wire which constitutes one member of the combined service bell push and alarm circuit above mentioned, while of the other leads controlled by the respective circuit closers, one constitutes the second member of the same combined service bell push and alarm circuit and another constitutes the corresponding member of a corridor alarm circuit having the same common return. By this arran ement, an alarm of fire in any apartment wil be automatically notified both by the service and corridor (or fire station) bells and indicators as hereafter explained.

According to the preferred construction the thermostat instrument D comprises a metal base or frame cl connected to the common return wire, and two inde endent horizontal strips J, K of metal eac secured between fixed points on the base or frame so that the strip when expanded by heat will sag downwards from its normal position and, upon the rise of temperature producin a predetermined deflection of the strip, the atter will come into contact with a stop formed by an electrical terminal in circuit with the corresponding member of the automatic alarm circuit, this circuit being consequently closed and the alarm given.

The terminal constitutin the stop in the case of each stri consists o a set screw carried by, but insu ated from, the metal base of the instrument, and capable of bein adjusted relatively to the level of the strip for the purpose of determinin the amount of deflection and consequent y the degree of been set.

In the example illustrated the base at of the thermostat D has two terminals d, j whereof d is connected by a wire 3 with the terminal a of the service bell push A, while j is connected by a wire 4 with the wire 1 which, although originally coupled to the terminal a, has been disconnected therefrom as already mentioned. The wire 1 is coupled to one terminal of the service indicator L whose other terminal is connected by the wires 5, 6 with one pole of the battery H whereof the other pole is connected by the wire 7 with one terminal of the service bell B. The other terminal of this bell is connected to the wire 2 which, although originall r coupled to the terminal a of the service bel aush A, has been disconnected therefrom as al ready mentioned, the terminal a. and the wire 2 being now independently connected by the wires 8 and 9 respectively, with the adjustable screw terminal cl of the thermostat D, whereof the flexible metal strip J is ada ted, on being expanded by a predetermine increase of temperature within the apartment, to sag down and make electrical contact with the terminal d.

In consequence of the arrangement above described, every time the service bell push A is operated, the current whereby the service bell B is rung and the service indicator C is actuated will pass through the entire length of the thermostat leads appertaining to the bell ush A, the current passing (in the examp e illustrated) from the battery H by way of wire 7 to the bell B, thence by wires 2 and 9 to the thermostat adjustable terminal cl, thence by wire 8, terminal (1 service push A, terminal a, wire 3, thermostat terminal d base d, terminal 3', wire 4, the service indicator C, and wires 5 and 6 back to the battery H. By this means there is afforded, at every actuation of the service bell push A, a test as to the whole system of wiring through which, on the thermostat strip J coming into action in case of fire, an alarm would be conveyed to those within the building where the a artment is situated. Such an alarm woul of course be sounded by the service bell B and visually notified by the service indicator C appertaining to the a artment in question, but automatically, an altogether independently of the actuation of the service bell push A, the current passing in this case from the battery H by Way of wire 7 to the bell B, thence b wires 2 and 9 to the thermostat adjusta le terminal (1, thence by stri J, thermostat lame a, 9', wire 4, indicator 0, and wires 5 and 6 back to the battery H.

The flexible metal strip K of the thermostat D is ada ted on being expanded by a predetermine increase of temperature, to sag down and make electrical contact with the adjustable screw terminal is, whereof the construction is similar to that of the adjustable terminal d already referred to. This adjustable terminal lc is connected by the wire 10 with the terminal e of the corridor or other fire-alarm push E which is also connected by wire 11 to one terminal of the fire station (or other) indicator G whose other terminal is connected by wire 12, through the fire station hell or other alarm ap iaratus l and wire 13, with the wire 7 which leads to one pole of the battery H. The other terminal e of the corridor push E is connected by wire 14 with the wire 6 which leads to the op iosite pole oi the battery.

*hen the corridor push E is actuated, current passes from the battery H by wires 7 and 13, station bell F, wire 12, station indicator G, wire 11, terminal 6, )ush E, terminal c and wires 14 and 6 bac to the battery H. Should a fire occur in the apartment however, on the redetermined tem- 'perature being attained t e strip K bysagging down so as to make contact with the adjustable terminal is will close the circuit through the bell F and indicator G independently of the actuation of the push E, the current then passing from the battery H throu h wires 7 and 13, bell F, wire 12, indicator wire 1] terminal a, wire 10, terminal 7r, strip K, thermostat base d, terminal 7', wires 4 and 1, indicator C, and wires 5 and 6 hack to bat ter H.

laims.

1. A combined service electric bell system, and automatic electric fire alarm system, consisting in combination with a service electric bell circuit, of a thermostat whose normally separated elements are permanently in series with the res ective members of said bell circuit, so that t ie sounding of the service bell when said circuit is operated will indicate that the current has passed through the circuit of the said thermostat elements, as specified.

2. An automatic electric fire-alarm system comprising a service electric bell circuit, a thermostat circuit, and a corridor electric bell circuit, the thermostat being provided with a common return wire for all the eircuits, and other leads controlled by the service and corridor circuit closers, so that the respective bells ma be operated independent y of each other by the res ective circuit closers or concurrently by t e thermostat substantially as specified.

An automatic fire alarm. omprising a thermostat havinga plurality of circuit closers adapted to be actuated at different temperatures, a service bell circuit ridor bell circuit independently of the theradepted to be operated by one of the circuit mostat.

closers of the thermostat, means for operating the service bell circuit independent of the thermostat, a corridor bell circuit adapted to l Witnesses: be operated by the other circuit closer of the l R. \VESTAGOTT, thermostat, and means for operating the corl H. l). JAMESON.

CHARLES JAMES FOX. 

